The southern bigmouth bass, commonly known as the river buzzard, is rich in flesh and meat, delicious in flesh, less thorns, fast growing, and large in size. It is a kind of freshwater fish with high economic value. In recent years, many farmers in Guangdong, Sichuan, and Guangxi have cultivated the economy. The benefits are significant.
1 The Biological Characteristics of the Southern Bigmouth Fever
1.1 Classification status and distribution Silurus Soldatoui Meridio Nalis Chen is a genus of the genus Oviformus, Acipenseridae, and Eucalyptus, which are mainly distributed in Guangdong, Guangxi, Sichuan, Hunan and Hubei.
1.2 Main morphological features The southern part of the mouth is slightly flattened with no scales, mucus is abundant in the skin, the upper part of the mouth is wide, and the crack reaches or exceeds the lower part of the central part of the eyeball. There are many velvet-like fine teeth in the maxillary and mandibular and the vomer. Three pairs of fish), the maxillary must reach the base of the pectoral fin, the pectoral fin has a 2-3 row of granular protrusions on the leading edge, the dorsal fins are short and unstabbed, the anal fins are connected with the pectoral and caudal fins, the caudal fins are asymmetric, and the upper leaves are longer than the lower leaves.
1.3 Habits of life The southern bigmouth owl mostly inhabits rivers and gentle flow areas. They are fierce. When they are young, they like to cluster. They often hide in the water or lurk in caves during the day. They often hunt fish, shrimps and other aquatic animals at night.
1.4 Breeding habits In the breeding season of rivers from April to June, artificially cultivated broodstock can be matured before mid-March and late. It can lay eggs 2-3 times a year. Spawning requires a water temperature of 18-28°C. The eggs are oily yellow, and they are highly viscous.
2 Artificial reproduction of the southern estuary
2.1 Bred by broodstock The brooding brooding bream of the South has a large individual size. The mature broodstock has a body length of 700 mm or more and the amount of cocking eggs is relatively large. Therefore, the number of broodstock and the size of the selected broodstock must be taken into consideration in order to avoid increasing the cost. . Water quality should not be fat, stocking density is 100-250kg, live fish as bait, bait fish specifications 25-30cm in length, daily feeding amount 5-6% of its own body weight, broodstock male and female stocking ratio of 3:2 , pay attention to changing the water.
2.2 broodstock selection and male and female identification Mature female abdomen enlargement, loose, uniform upper and lower abdomen, reproductive hole swollen, reddish, gently press the abdomen by hand elastic, male fish gently press the abdomen with oily yellow semen outflow.
Identification of male and female: Female individuals are significantly larger than males. External genitalia resembles peaches. They are round-circular, males are small, and their bodies are dark. External genitalia are slightly longer and prominent.
2.3 There are PG, LRH-A, DOM and so on for artificial oxytocin production. The use of PG+LRH-A or DOM+LRH-A has a good effect. Dosage: Female PG 1.5-2.5 tablets + LRH-A 30-40ug/kg or DOM3-5mg + LRH-A 30-40ug/kg. The male dose is halved. The use of intrapleural injection, the female split into two injections, spawning effect time is relatively stable; the first injection dose of 30% of the full dose, a second injection about 8 hours apart, the male fish can be injected once, the dose reduced by half, Dispense after injection. The broodstock was stimulated after the injection.
2.4 Egg-laying fertilized viscous eggs, using artificial insemination and attention to agitation. Incubation: fresh water, high dissolved oxygen, water flow, small cage hatching, even distribution. On the third day after the larvae came out of the membrane, the yolk disappeared and they started feeding.
2.5 Seedlings The larvae were cultured as long as 1 cm and transferred to seedlings. Use cages and cement pools in two ways. It requires fresh water and high dissolved oxygen.
2.5.1 Cage Incubation Cage uses different specifications of 60 mesh and 45 mesh, and the depth of water is 80cm to 1m. It takes about 13 days from 1cm to 5cm in body length to take leeches, red worms, egg yolks and quail as bait. The stocking densities ranged from 5000 to 1000-1500 tails/m3 in descending order, and then 4-5 batches of fry or fish paste were used as bait.
2.5.2 The cement tank is to be cultivated for a depth of 1m and stocked for 150-200 tails/m3. The water is often changed and the feed is the same as above. In addition, pay attention to measures: (1) feed more than once, cast enough feed. (2) Add shading facilities, or put daffodils, often sieving and cultivating specifications. (3) Regular quarantine, timely bathing with copper sulfate solution (concentration 1ppm).
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